ball joint

ball-and-socket joint

[bawl-uh n sok-it] /ˈbɔl ən ˈsɒk ɪt/

noun

1.

Also called enarthrosis. Anatomy, Zoology. a joint in which the rounded end of one bone fits into a cuplike end of the other bone, allowing for relatively free rotary motion, as at the hip or shoulder.

2.

Also called ball joint. a similar joint between rods, links, pipes, etc., consisting of a ball-like termination on one part held within a concave, spherical socket on the other.

ball-and-socket jointn. A multiaxial joint in which a sphere on the head of one bone fits into a rounded cavity in the other bone, as in the hip joint. Also called cotyloid joint, enarthrodial joint, enarthrosis, spheroid joint.

A joint, such as the shoulder or hip joint, in which a spherical knob or knoblike part of one bone fits into a cavity or socket of another, so that some degree of rotary motion is possible in every direction.

A mechanical device consisting of a spherical knob at the end of a shaft that fits securely into a socket. Ball-and-socket joints are used to connect parts of a machine that require rotary movement in nearly all directions. Ball-and-socket joints allow the front wheels of a car to be turned by the steering mechanism.